Improvement in screw-propellers



UNITED j- STATES PATENT EDWIN J. HUIJBERT, OF'MIDDLETOWN, CONNECTICUT.

IMPROVEMENTIN SCREW-PROPELLERS. V

Specification forming part of Letters Patent No. 199,549, dated January22, 1878;. application filed July 12, 1877. v k

To all whom it may concern:

Be it known that I, EDWIN .LHULBERT, of Middletown, Middlesex county,Connecticut, have invented an Improvement in Wheels for Propellers; andI do hereby declare the following to be a full and correct descriptionof the same, reference being had to the accompanying drawings, in which-Figure 1 is a side view, partly in section, of my improved propellerwheel, showing the blades adjusted to their maximum pitch 5 and Fig. 2shows said blades at their minimum pitch. Figs. 3 and 4 show theposition of a blade upon its two arms; and Fig. 5 is a rear view of thewheel, showing its position on the shaft.

My present invention is an improvement upon an invention for which theUnited States Patent Office has allowed a patent and it consists in amode of adjustment for adjusting the blades of a propeller-wheel to aless or greater degree of pitch, whereby the position of the blades maybe adapted to the particular degree of speed or power desired in thevessel propelled.

In the drawings, A represents the engineshaft of a propeller, upon theouter or rear end of which the wheel is located. Upon the extreme rearend of the shaft A is securely fixed the hub B, and sliding freely uponthe shaft A is the hub C, with a forward extension, D. Said hub C has aset-screw, by which it may be fixed upon the shaft A when it may becomenecessary. In either side of the hubs B and C are lugs (0, upon whicharms E E and F F freely revolve. Stay-screws pass through the severalarms and travel through the groove around the lugs to, allowing the armsto freely revolve, but preventing any longitudinal motion. Ascrew-thread being out upon the forward extension D of the hub C, a malescrew is formed, which enters the female collar G. The collar G turnsfreely upon the shaft A.

' A lateral movement is again prevented by a stay-screw and groove inthe shaft A. The. arms E and'F, at their outer ends, are bent backwardat an angle, and upon these bent ends are adjustably fixed the blades HH. Said blades H H are of a helicoidal form, and are secured to the armsE and F in the following manner: The center of the blade H is secured tothe arms E and F by abolt, e, passin g through the blade, thence througha washer, and finally through the arm E or F, as 'the case may be. Uponeither side of the bolt 0 is the bolt f or g, which passes through theblade and arm without the washer but where the bolts f and 9 passthrough the blade H the hole is elongated longitudinally with the blade,so as to give the blade a circular movement upon the bolt 6.

The operation of my mode of adjustment is as follows: The hub B beingfixed upon the shaft A, and the hub C movable upon said shaft, and theblades H pivoted upon the ends of the rotating arms E and F, which aresecured to the hubs B and C, but are permitted to make partialrevolution on the lugs to, it is obvious that a movement of the hub Cupon the shaft A will change the pitch or draft of the blades H; and, asthe blades H are helicoidal in form, the whole relative position of theblades upon the arms and the arms upon the hubs will be changed when theposition of the hub C is changed upon-the shaft A. In Fig. l the maximumdistance between the hubs B and C is shown. The bolts f and 9 havingbeen loosened, the blade H upon the arm E will assume the position shownin Fig. 3, ithaving rocked upon the bolt 6, with its outer edge restingupon the arm E and the inner edge removed from it, while the blade uponthe arm F will assume the opposite position, as shown in Fig. 4, theinner edge resting upon the arm F and the outer edge re moved from it.Let the female collar G be now rotatedthe threaded extension D will beexpelled, and the hub C will approach the hub B, as in Fig. 2, where theminimum distance between the hubs B and C is shown.

In this motion the arms E and F have made part of a revolution upon thelugs a, and the blades H have rocked and revolved upon the bolts 6, sothat they assume the opposite from that shownin Fig. 1-namely, the bladeupon the arm E will take the position shown in Fig. 4E, and the bladeupon the arm F will assume the position shown in Fig. 3. The meandistance between the hubs B and C will, of course, show the bladesparallel with the end of the arms in every case.

The bolts f and g are to be loosened prior to adjustment, to admit ofthe rocking motion on 0; after adjustment, to be set to aid inretainingitheradjustment andw'to efiect more complete rigidity of thewheel.

Having thus fully described my invention, what I claim, and desire tosecure by Letters Patent, is-

1. The blades of a propeller-wheel pivoted upon the backwardly-inclinedends of self-adjusting arms upon adjustable hubs, substantially asdescribed.

2. Helicoidally-shaped blades of a propellerwheel, pivoted upon thebackwardly-inclined ends of self-adjusting arms by means of the centerpivot-bolt e and guide-bolts f and g, op erating in slots, substantiallyas described.

3. The helicoidally-shaped blades of a propeller-wheel, pivoted tobackwardly-inclined arms, as described, and provided with awasher uponthe pivotbolt between the blade and arm,

EDWIN JAMES HULBERT.

I Witnesses:

FRANK F. STARR, H. W. B. STARR.

